strcpy allows null-terminated memory blocks to be copied to different locations. Since, in C, strings are not first-class datatypes, and are implemented as blocks of ASCII bytes in memory, strcpy will effectively copy strings given two pointers to blocks of allocated memory.

memcpy

memcpy() works on arbitrary data of a given fixed length

use memcpy() when you want to copy an exact amount of data (possibly containing embedded null chars) from one location to another, and strcpy() when you want to copy a variable-length null-terminated C string from one location to another...

Quote:

Originally Posted by prem_may10

2. what is memory leak?

Memory leaks are often thought of as failures to release unused memory by a computer program. Strictly speaking, it is just unneccesary memory consumption. As an example Making malloc calls without the corresponding calls to free.

Quote:

Originally Posted by prem_may10

3. what is the difference between general operating system and real time operating system.

OS which performs the task in the real time environment. As an example say you need to embedded applications (programmable thermostats, household appliance controllers, mobile telephones), which cannot take more than a specified time to complete an operation but your normal OS can.